The overall goal to this project is to create an integrated system for the expression, detection and rapid purification of proteins from cloned genes. The foundation for this system is a highly engineered subtilisin which hydrolyzes substrates in response to a chemical trigger. The subtilisin prodomain (protag) will be developed both for detection of native target protein and as the ligand for affinity purification. The engineered processing subtilisin (psub) will be used both as the binding molecule for affinity purification of protagged fusion proteins and as the processing protease for protag removal. The long range objective is to develop a sophisticated set of tools to facilitate proteomic analysis in the way restriction endonucleases have been used to facilitate genomic analysis. [unreadable] [unreadable]